Apparatus for inflating and sealing air-filled packing cushions

ABSTRACT

A machine which inflates and seals pillows in packaging is compact in overall size, can be conveniently operated to produce varied lengths of strips of inflated pillow-type packaging as needed, can begin production of inflated pillow-type strip packaging immediately after being held out of a production cycle for some period of time, and applies a heated sealing element directly to and in sliding contact with a web of film to securely seal the inlet port of an inflated pillow while the pillow is under pressure and as the web of film is continuously and uninterruptedly advanced through the machine.

BACKGROUND OF THE INVENTION

[0001] This invention relates to methods and apparatus for inflating andsealing pillows in packaging.

[0002] This invention relates particularly to the construction andoperation of a machine which is small enough to be installed foroperation on site where articles packaged for transport are placed inshipping containers with protective inflated pillow-type strippackaging.

[0003] This invention relates particularly to a machine which is compactin overall size, which can be conveniently operated to produce variedlengths of strips of inflated pillow-type packaging as needed, which canbegin production of inflated pillow-type strip packaging immediatelyafter being held out of a production cycle for some period of time andwhich applies a heated sealing element directly to and in slidingcontact with a web of film to securely seal the inlet port of aninflated pillow while the pillow is under pressure and as the web offilm is continuously and uninterruptedly advanced through the machine.

[0004] This invention relates particularly to a machine which forms theseal complete and secure during a short path of travel and during ashort interval of time. The seal is made without the need for additionalpressing together of the film after the sealing and without the need foradditional cooling of the seal after the sealed inlet port moves out ofcontact with the sealing structure.

[0005] Webs of plastic film which are constructed to permit theproduction of strips of air filled envelopes, cushions and pillows have(in the past ten years or so) been used extensively for cushioningobjects to be transported in containers.

[0006] The thin webs of plastic film are inexpensive, tough, resilientand recyclable. Strips of inflated pillow packaging which are createdfrom these webs of plastic film are used for void-fill packaging toreplace products such as crumpled paper or polystyrene peanuts and forprotective packaging to replace molded or extruded foams.

[0007] U.S. Pat. No. 5,454,642; U.S. Pat. No. 5,651,237; U.S. Pat. No.5,755,328; U.S. Pat. No. 4,017,351; and U.S. Pat. No. 5,824,392 disclosemethods, apparatus, and webs of plastic film used for making strips ofinflated pillow packaging of this general kind. Each of these U.S.patents is incorporated by reference in this application.

[0008] Co-pending application Ser. No. 09/207,129 filed Dec. 8, 1998 andentitled “Method and Apparatus for Manufacturing Air-Filled SheetPlastic Shipping Cushions and the Like”, Nicholas P. De Luca and AndrewPerkins, inventors and co-pending application Ser. No. 09/439,552 filedNov. 12, 1999 and entitled “Machine and Method for Manufacturing aContinuous Production of Pneumatically Filled Inflatable PackagingPillows”, Andrew Perkins, Philipp Borchard, and Nicholas P. De Luca,inventors also disclose methods, apparatus and webs of plastic film ofthis general kind. Each of these two co-pending applications is assignedto the same assignee as the assignee of this application. Each of thesetwo co-pending applications is incorporated in this application byreference.

[0009] Sealing an inflated pillow made a web of plastic film while theair inflates the pillow under pressure and while the web of plastic filmis being transported through the machine presents problems.

[0010] The seal must be secure and must not leak in order for theinflated pillow packaging to be used effectively for cushioning objectstransported within a container.

[0011] The seal needs to be formed efficiently, quickly and withoutextensive, related pressing and/or cooling structure in order to makethe machine as compact as possible in size and as efficient as possiblein production rate.

[0012] To simplify machine construction and to provide a high efficiencyof production, it is desirable to be able to make the seal as the web ofplastic film is moved continuously and without any interruption and/orintermittent stopping of the film transport during the sealingoperation.

[0013] It is a primary object of the present invention to construct andto operate a machine which is compact in size, which is efficient inproduction, which is continuous and uninterrupted in operation and whichproduces seals which are secure and which do not leak.

SUMMARY OF THE PRESENT INVENTION

[0014] In a specific embodiment of the present invention, a machineinflates and seals pillows in packaging while continuously anduninterruptedly advancing a web of film through an inflating station anda sealing station. The inflating station sequentially inflates pillowsat preformed patterns in the web of film by introducing pressurized airthrough a narrow width inlet port of a preformed pattern. The sealingstation seals each inlet port by applying a heated sealing elementdirectly to and in sliding contact with the web of film while the air inan inflated pillow is under pressure as the inlet port moves across theheated sealing element.

[0015] The web of film has an uninflated pillow pattern and anuninflated inflation channel preformed in the film. The uninflatedpillow patterns comprise multiple, spaced apart, pillow patterns alignedalong one side of an inflation channel. The inflation channel extendslongitudinally and continuously along the entire length of the film.Each uninflated pillow pattern has a narrow width inlet port extendinggenerally transversely to the longitudinally extending inflation channeland connecting the uninflated pillow pattern to the uninflated inflationchannel so that, when pressurized air is introduced into the inflationchannel, the pressurized air can be transmitted through the inlet portto inflate the pillow pattern. In some cases the preformed pattern isalso formed with outlet ports connected to the inflation channel in sucha way that air entering the inflation channel can move into a pillowthrough an inlet port and can also exit out of the inflation channelthrough the outlet port. The outlet port is generally shaped smallerthan the inlet port.

[0016] By allowing the air above a desired pressure to escape through anoutlet port or ports, the pressure in the inflation channel ismaintained at a desired level for inflating the pillows without creatingover-pressurization.

[0017] The air escaping through the outlet port is also sensed to detectwhere the pillows are in the machine. These detected outlet portpositions are then used as signals for an associated electronic unit tocount the number of pillows inflated in a particular run through themachine. This also facilitates being able to stop the movement of thefilm through the machine after one production run of a selected numberof inflated pillows at a position which is the right position to start asubsequent production run of a selected number of inflated pillows.

[0018] In a specific embodiment of the present invention, the web offilm with the preformed patterns is stored on a storage roller of themachine and is advanced through the machine by a first set of niprollers and a second set of nip rollers at a respective first filmtransport station and a second film transport station.

[0019] Pressurized air is introduced into the inflation channel of theweb of film at an inflating station as the web of film is transportedthrough the first film transport station. The pressurized air inflatesat least one of the pillow patterns prior to the time the web of film iscontinuously transported through a sealing station.

[0020] Pressure is maintained in the inflated pillow pattern within acalibrated pressure range during the time that the web of film iscontinuously transported through the sealing station.

[0021] At the sealing station the inlet port of an inflated pillow issealed by applying a heated sealing element directly to and in slidingcontact with the web of film. The heated sealing element slides acrossthe inlet port while the air in the inflated pillow is under pressureand as the web of film is continuously and uninterruptedly advancedthroughout all components of the machine.

[0022] The heated sealing element has a relatively small longitudinaldimension in the direction of movement of the web of film. In a specificembodiment the length of the heated sealing element is about the same asthe width of the inlet port of a pillow pattern. This small size of theheated sealing element helps minimize the amount of sealing heat appliedto the web of film.

[0023] The sealing station includes a sealing roller disposed alongsidethe heated sealing element so as to permit the web of film to beadvanced between the sealing roller and the heated sealing element.Adjustable biasing means provide for adjustment of the force with whichthe heated sealing element and the sealing roller are pressed towardengagement with one another.

[0024] The sealing roller is positioned with respect to the first andsecond pairs of nip rollers so as to cause the web of film to wraparound a part of the peripheral surface of the sealing roller both in acircumferential direction and also in a lateral direction. This helpscreate a dead and flat zone right at and adjacent to the line of sealingacross the inlet port. This in turn facilitates making a secure sealwithout leaking while the pillow is inflated under pressure.

[0025] The axes of rotation of at least the second pair of nip rollersare preferably canted at a slight angle with respect to the axis ofrotation of the sealing roller.

[0026] The second pair of nip rollers are preferably rotated at a speedslightly faster than the speed of rotation of the first pair of niprollers so as to maintain tension in the web of film between the secondand first pair of nip rollers.

[0027] In one specific embodiment of the present invention the heatedsealing element is a fabric covered Nichrome wire disposed at the end ofa bar element which is biased toward engagement with a sealing roller.The fabric covering of the Nichrome wire has a Teflon coating on itsouter surface for facilitating sliding of the heated sealing element onthe engaged surface of the film as the web of film is advanced throughthe machine.

[0028] The bar on which the heated sealing element is mounted is acomposite bar. The very tip of the bar is a ceramic having goodinsulating qualities, and the remainder of the bar is a differentmaterial selected to provide enhanced mechanical durability.

[0029] The seal is formed complete and secure during a short path oftravel through the sealing station.

[0030] The seal is complete and secure at the time the web of film movesout of contact with the wheel at the sealing station and without theneed for additional pressing together of the film after the sealingstation and without the need for additional cooling of the film acrossthe sealed inlet port after the sealed inlet port moves out of contactwith the sealing station.

[0031] In a second specific embodiment of the present invention thesealing wheel is pressure biased toward engagement with the heatedsealing element.

[0032] In both the first and second specific embodiments the heatedsealing element and the sealing wheel are spaced apart from one anotherwhen the machine is not transporting the web of film through the machinein a production run. This enables the heated sealing element to bemaintained at a desired temperature level while preventing contact withand possible burning of the unmoving film at the sealing station.

[0033] In one specific embodiment of the invention the fabric coveringfor the Nichrome wire is held in a fixed position at the end of the barelement and is replaced as needed.

[0034] In another specific embodiment of the invention the heatingstation includes a cartridge unit which can be quickly and easilyinterchanged with another cartridge unit. The cartridge unit includes anelongated strip of the fabric covering. The strip is mounted on tworotatable reels. The fabric always covers the Nichrome wire, as in thefirst specific embodiment, and the fabric has a Teflon coating on theside which engages the film in sliding contact, as in the first specificembodiment. The elongated strip of fabric covering is wound between thetwo reels so as to be moved across the length of the Nichrome wire at aspeed which is much slower than the speed of movement of the filmthrough the machine but which is fast enough to ensure that the coveringstrip of fabric is always effective to function properly without anyburn through of the fabric or damage to the film from the heatedNichrome wire. The cartridge unit permits the Nichrome wire of theheated sealing element to be easily disconnected from its power supply.The cartridge units are constructed to be readily interchanged as units,rather than having to replace individual components of the cartridgeunit.

[0035] Methods and apparatus which incorporate the features noted aboveand which are effective to function as described above comprisefurther,. specific objects of this invention.

[0036] Other and further objects of the present invention will beapparent from the following description and claims and are illustratedin the accompanying drawings, which by way of illustration, showpreferred embodiments of the present invention and the principlesthereof and what are now considered to be the best modes contemplatedfor applying these principles. Other embodiments of the inventionembodying the same or equivalent principles may be used and structuralchanges may be made as desired by those skilled in the art withoutdeparting from the present invention and the purview of the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWING VIEWS

[0037]FIG. 1 is an isometric view of a machine, constructed inaccordance with one embodiment of the present invention, for inflatingand sealing pillows in packaging. FIG. 1 is a general view whichillustrates how a web of film is transported through the machine. FIG. 1shows how the web of film has a preformed pattern of spaced-apart,inflatable pillows aligned along one side of a longitudinally extendinginflation channel. FIG. 1 illustrates how rollers (at a first transportstation, at a sealing station, and at a second transport station) arepositioned to engage the underside (as viewed in FIG. 1) of the web offilm.

[0038]FIG. 2 is another isometric view of the machine shown in FIG. 1,but in FIG. 2 the lower part of the figure has been revised to (ineffect) see through the web of film in order to show details of certainstructure of the machine. FIG. 2 shows the inflation tube of theinflating station, the nip rollers of the first transport station, theheated sealing element and the associated sealing roller at the sealingstation, and the nip rollers at the second transport station.

[0039]FIG. 3 is an isometric view of the machine of FIGS. 1 and 2, butwithout the web of film material. FIG. 3 shows the main structural andoperative features of the machine itself.

[0040]FIG. 4 is an isometric, enlarged view showing details of thefeatures of the first film transport station, the inflation stationstructure, the sealing station structure, the slitting stationstructure, and the second film transport station structure.

[0041]FIG. 5 is an isometric, enlarged view like FIG. 4 but showsdetails of just the mechanism for driving the various rollers of themachine. FIG. 5 does not show the inflation station structure, theheated sealing element at the sealing station, or the slitter structurefor opening up the inflation tube of the web of film after the sealingstation.

[0042]FIG. 6 is an isometric view showing details of the structure ofthe sealing station. FIG. 6 shows the heated sealing element pressedtoward engagement with the sealing wheel in the positions occupied bythose two components during a production run of the inflated pillowpackaging through the machine.

[0043]FIG. 7 is a top plan view, taken along the line and in thedirection indicated by the arrows 7-7 in FIG. 6, but showing the heatedsealing element retracted away from the sealing wheel in the positionsoccupied by those two components when no film is being transportedthrough the machine.

[0044]FIG. 8 is a top plan view of a specific embodiment of a web offilm constructed in accordance with the present invention and having aspecific pattern of inflatable pillows, inlet ports for permittinginflation of the pillows, and escape ports for preventing overpressurization of the pillows and for also permitting more accurateposition sensing of the pillows as the web of film moves through themachine.

[0045] FIGS. 9A-9G are a series of the isometric views showing detailsof the structure, components and sequence of assembly of certaincomponents of the heated sealing element at the sealing station.

[0046]FIG. 10 is an isometric view of a machine constructed inaccordance with a second embodiment of the present invention. Theembodiment of the machine shown in FIG. 10 includes a cartridge unitwhich is mounted on a separate sub-plate or sub-frame and which permitsall of the components of the cartridge unit to be quickly and easilyremoved and replaced by another, replacement cartridge unit. Thecartridge unit provides the heated sealing element components for thesealing station. FIG. 10 shows the sealing wheel of the sealing stationpositioned to engage the web of film in sliding contact with the heatedsealing element during a production run of packaging.

[0047]FIG. 11 is an isometric view like FIG. 10 but showing the sealingwheel moved to a retracted position which permits the web of film tomove out of contact with the heated sealing element when the machine isstopped between production runs and the film is not being transportedthrough the machine.

[0048]FIG. 12 is an enlarged, isometric view of the replaceablecartridge unit itself. FIG. 12 shows the strip of covering fabric instored positions on the reels of the cartridge unit prior toinstallation of the cartridge unit in the machine. When installed in themachine, a portion of the strip of covering fabric is positioned overthe wire of the heating element (as illustrated in FIGS. 10 and 11).

[0049]FIG. 13 is an enlarged, isometric view of the sealing wheel andthe related actuator mechanism for positioning the sealing wheel at thesealing station.

[0050]FIG. 14 is an enlarged, side elevation view of the sealing stationstructure with the structure in the operative position shown in FIG. 10;and,

[0051]FIG. 15 is an enlarged, side elevation view of the sealing stationstructure with the structure in the non-operating position shown in FIG.11.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0052]FIGS. 1, 2 and 3 are isometric view of a machine, constructed inaccordance with one embodiment of the present invention, for inflatingand sealing pillows in packaging.

[0053] The machine is indicated by the general reference numeral 11 ineach of FIGS. 1, 2 and 3.

[0054] The machine 11, as most easily viewed in FIG. 3, comprises a mainplate 13 on which various structural and operational features aremounted.

[0055] A support tube 15 is mounted at the upper (as viewed in FIGS.1-3) of the main plate 13 for supporting a roll 17 of a web of film 19(see FIGS. 1 and 2).

[0056] Guide tubes 21 and 23 are mounted on the plate 13 below the tube15. The tubes 21 and 23 serve to guide the web of film 19 from the roll17 to the operating mechanism 25 of the machine 11. The operatingmechanism 25 is described in more detail below.

[0057] The mechanism 25 is illustrated in detail in FIG. 4 and comprisesa first film transport station 27, a second film transport station 29,an inflating station 31, a sealing station 33, and a slitting station35.

[0058] The first film transport station 27 includes a first pair of niprollers 37 and 39 for gripping the web of film 19 (see FIG. 1) and forpulling the web of film 19 from the roll 17 and under and over the guidetubes 21 and 23 and through the first film transport station 27 when thenip rollers are rotated by associated drive gears 41, 43 and a drivebelt 45. The nip rollers 37 and 39 are rotated in the directionsindicated by the direction arrows on the drive gears 41 and 43 shown inFIG. 4.

[0059] The drive belt 45 is driven by a drive gear 47 which is in turndriven by a motor 49 (see FIG. 5).

[0060] The second film transport station 29 comprises a second pair ofnip rollers 49 and 51 which grip the web of film 19 to continuouslyadvance the web of film 19 from the first transport station 27 to andthrough the inflating station 25 and to and through the sealing station33 and then to and through the second film transport station 29.

[0061] The nip rollers 49 and 51 are driven by drive gears 53 and 55 andin the rotational directions indicated by the directional arrows on thedrive gears 53 and 55 in FIG. 4.

[0062] Drive shafts 40 and 44 transmit the drive from the drive gears 41and 43 to the nip rollers 37 and 39.

[0063] Drive shafts 50 and 52 transmit the drive from the drive gears 53and 55 to the nip rollers 49 and 51.

[0064] With continued reference to FIG. 4, the drive belt 45 passesabout an idler gear 57. The drive gears 41, 43, 47, 53, 55 and idlergear 57 are all mounted for rotation on and are supported by the mainplate 13.

[0065] The inflating station 31 includes an inflation tube 59 and agenerally spherically shaped and partially Teflon coated ball 61 locatedat the upper end (as viewed in FIG. 4) of the tube 59. The ball 61 has aplurality of openings 63 for injecting pressurized air into an inflationchannel in the web of film 19.

[0066] As illustrated in FIGS. 1, 2 and 8, the web of film 19 as storedon the roll 17 shown in FIG. 1 has a pattern of pillows 65, alongitudinally extending inflation channel 67, inlet ports 69, andoutlet ports 71 preformed in the web of film. The pillows 65, channel67, ports 69 and ports 71 are uninflated in the web of film as stored onthe roll 17.

[0067] The uninflated pillow patterns 65 are longitudinally spaced apartfrom one another and are aligned (in the embodiment of the web of film19 illustrated in the drawings) along one side of the inflation channel67.

[0068] The inflation channel 67 extends longitudinally and continuouslyalong the entire length of the web of film 19.

[0069] The inflation channel 67 is dimensioned to provide a close,sliding fit over the Teflon coated ball 61.

[0070] Each pillow 65 is connected to the inflation channel 67 by aninlet port 69. The inlet port 69 extends generally transversely to thelongitudinally extending inflation channel 67 and has a narrow interiorwidth which is positioned at the sealing station 33 (in a manner to bedescribed more fully below) to facilitate quick and secure sealing ofpressurized air within an inflated pillow 65 in a small path of traveland in a short time of continuous, uninterrupted travel through thesealing station 33.

[0071] The outlet ports 71 are shaped to be somewhat smaller than theinlet ports 69. These outlet ports 51 are located on the side of thechannel 67 opposite the inlet ports 69 and are generally aligned withthe inlet ports 69.

[0072] As will be described in greater detail below, the outlet ports 71allow air to escape in a way to maintain pressure in the channel 67 andin the inflated pillows at a calibrated, desired level without creatingover-pressurization in the pillows.

[0073] In addition, the air that exits from an outlet port 71 can besensed by a pressure transducer 73 (see FIG. 8) to allow for accurateposition sensing of the pillows as the pillows move through the machine11.

[0074] The air escaping through the outlet ports is sensed to detectwhere the pillows are in the machine. These detected outlet portpositions are then used as signals for an associated electronic unit tocount the number of pillows inflated in a particular run through themachine. This also facilitates being able to stop the movement of thefilm through the machine, after one production run of a selected numberof inflated pillows, at a position which is the right position to starta subsequent production run of a selected number of inflated pillows.

[0075] The upper end of the inflation tube 59 is formed with a smallcurvature so as to better follow the path of the film 19 as the film isadvanced through the first transport station 27 and the sealing station33.

[0076] Details of the construction and mode of operation of the sealingstation 33 are illustrated and will be described with reference to FIGS.4, 6 and 7.

[0077] The sealing station 33 comprises a sealing roller 75 mounted on ashaft 77 which is in turn mounted for rotation in a bearing assemblyattached to the main plate 13.

[0078] The sealing station 33 also comprises a heated sealing elementlocated at the outer end (the right hand end as viewed in FIG. 7) of abar 81. The very tip 80 of the bar 81 is a ceramic of aluminum silicateto provide an insulation function, and the remainder of the bar 81 is adifferent material selected for mechanical durability.

[0079] The bar 81 is mounted for sliding motion within a support 83.

[0080] A spring 85 and an adjustment screw 87 provide a selectable biasforce for biasing the bar 81 toward the opposed periphery of the roller75 so that the film 19 (in the longitudinally extending strip whichcrosses the inlet ports 69) is pressed in rolling contact with the outerperiphery roller 75 and in sliding contact with the end surface of thebar 81 as the first and second film transport stations continuouslyadvance the web of film 19 through the sealing station 33.

[0081] An actuator 89 is included in the sealing station 33 forretracting the bar 81 against the bias of spring 85 and away fromengagement with the roller 75 when the film 19 is not being advancedthrough the machine 11. This facilitates keeping the heating elementenergized at the proper heating level and out of contact with the film19 during time intervals when the machine 11 is not being used toproduce inflated pillow packaging.

[0082] Details of the structure, components and sequence of assembly ofcomponents of the heated sealing element are shown in the exploded viewsof FIGS. 9A-9F.

[0083] The heating element disposed at the end of the bar 81, in aspecific embodiment of the present invention, comprises at least oneNichrome wire 70 which runs vertically (as viewed in FIGS. 9A-9G) alongthe right hand end of the bar 81.

[0084] The Nichrome wire 70 at this location has a length about the sameas the throat width of an outlet port 69 in the film 19, and theNichrome wire 70 is covered by a fabric 72 having a Teflon coating onthe surface which contacts the film 19. The fabric covering 72 helps toform the wire 70 to a preferred shape for engagement with the film 19,and the Teflon coating facilitates sliding movement of the film 19 withrespect to the heated sealing element.

[0085] The heated sealing element comprises at least one Nichrome wire70, but (as illustrated in FIGS. 9A-9F) the present invention alsoencompasses using a plurality of parallel extending and laterally spacedapart Nichrome wires 70 for providing multiple seal lines across inletports 69 of the pillows 65.

[0086] As best illustrated in FIGS. 6 and 7, wires 91 and 93 conductelectricity to the Nichrome wire for heating the Nichrome wire.

[0087] The slitting station 35 (see FIG. 4) includes a blade 95 attachedto the inflation tube 59 and positioned to slit the inflation channel 67in the film 19 after the outlet port 69 of a pillow 65 has been sealedat the sealing station 33. This enables strips of inflated packaging tobe removed from the machine 11.

[0088] It is an important feature and benefit of the present inventionthat the components of the mechanism 25 and the coaction between thosecomponents enable a seal to be formed complete and secure in a shortpath of travel of the film through the sealing station 33 and in a shortperiod of time and without the need for additional pressing together ofthe web of film after the sealing station and without the need foradditional cooling of the seal across the inlet port after the sealedinlet port moves out of contact with the sealing station. The sealing ofthe inlet port at the sealing station is performed by applying theheated sealing element directly to and in sliding contact with the webof film and across the inlet port while the air and the inflated pillowis under pressure and as the web of film is continuously anduninterruptedly advanced through the mechanism 25 shown in FIG. 4.

[0089] A number of features of the present invention contribute toobtaining this efficient and beneficial sealing result.

[0090] As described above, the outermost tip of the bar 81 is a ceramicmaterial which functions as an insulator to help confine the heat of theheating element to substantially just the linear area of contact of thefabric covered Nichrome wire with the film 19.

[0091] The roller 75 is laterally offset outwardly (as viewed in FIGS.1-5) and is positioned with respect to the pairs of nip rollers 37-39and 49-51 so as to cause a bump in the film 19 at the sealing station33. This helps to create a dead zone adjacent the inlet port 69 to besealed by causing the web of film 19 to wrap around a part of theperipheral surface of the sealing roller 75 both in a circumferentialdirection and also in a lateral direction.

[0092] Driving the second pair of nip rollers 49-51 at a slightly higherspeed than the first pair of nip rollers 37-39 helps to insure that thefilm 19 is maintained flat and in substantially pressure sealingengagement with the periphery of the sealing roller 75.

[0093] As best shown in FIG. 5, the axes of rotation of at least thesecond set of nip rollers 49-51 are preferably canted at a slight upward(as viewed in FIG. 5) angle with respect to the axes of rotation of themain drive gear 47 and the sealing roller 75.

[0094] In a specific embodiment of the present invention the axes ofrotation of the first set of nip rollers 37-39 are also canted at thissame slightly upwardly inclined angle.

[0095] The inclusion and positioning of the outlet ports 71 (see FIG. 8)and the smaller size of these outlet ports contribute to allowing air toescape through the outlet ports in an amount to maintain sufficientpressure in the channel 67 without permitting over-pressurization inthat channel 67 or in the pillows 65.

[0096] The present invention permits sealing the inlet port at a sealingstation by applying a heated sealing element directly to and in slidingcontact with the web of film and across the inlet port while the air andthe inflated pillow is under pressure and as the web of film iscontinuously and uninterruptedly advanced through each of the firsttransport station, inflating station, sealing station, second transportstation and slitting station.

[0097] In FIGS. 1, 2 and 8 of the drawings the pillows 65 are shown in agenerally rectangular-shaped pattern. It should be noted, however, thatthe pillows 65 can be any preformed pattern configuration. The patternsof the pillows 65 can, for example, include preformed seal line elementswithin the interior of the pillows which permit the pillows to be foldedalong one or more of the preformed interior seal lines. This in turnpermits one pillow to cushion an object in more than one direction whenplaced within a shipping container.

[0098] Score lines (not illustrated in the drawings, but similar toscore lines shown in webs of plastic film described in numerous ones ofthe prior U.S. patents incorporated by reference in this application)permit ready detachment of single ones or groups of inflated pillowsfrom the film 19 after the pillows are inflated and sealed.

[0099] A number of different film compositions (also as noted in U.S.patents incorporated by reference in this application) can be used asthe composition material for the web of film 19.

[0100] The machines that are used to preform the patterns on the web offilm 19 include conventional presses which impress multiple pillowpatterns (and the related ports and inflation channel) on a strip offilm 19 on each pressing operation. The pattern is formed while there isno inflation pressure anywhere in the web 19.

[0101] The preformed pattern can also be formed by a roller arrangementin which at least one roller is heated and configured to form thedesired patterns.

[0102] Pattern forming machines of these kinds are also disclosed inseveral of the U.S. patents incorporated by reference in thisapplication.

[0103] Such machines for forming preformed patterns in the film 19 canbe associated with the machine 11 shown in FIG. 1 to replace the storageroll 17 so that the preformed patterns can be preformed continuously atthe site where the machine 11 is installed. However, in most cases it ismore practical to use a storage roll 17 with preformed patterns than itis to preform the patterns at the job site where the machine 11 is to beused.

[0104] A second embodiment of a machine constructed in accordance withthe present invention is illustrated in FIGS. 10-15 of the drawings.This second embodiment is indicated by the general reference numeral101.

[0105] The components and parts of the machine 101 which correspond tothe machine 11 shown in FIGS. 1-9 are indicated by correspondingreference numerals.

[0106] The machine 101 includes a cartridge unit 103 (see FIG. 12) whichis mounted on a separate sub-plate or sub-frame 105. The sub-frame 105is mounted on the main plate or main frame 13. This cartridge unittechnique permits the components of the entire cartridge unit to bequickly and easily interchanged (as a unit) with another replacementcartridge unit. Individual components of the cartridge unit do not haveto be removed and replaced.

[0107] In the machine 101 shown in FIGS. 10-15, the construction andmounting of the cartridge unit 103 permits the entire cartridge unit tobe pulled out of a box and plugged in as a unit at the production site.This cartridge unit permits all of the components of the cartridge unitto be replaced as a unit. It is never necessary, for example, to replacethe Nichrome wires as individual elements in the field. Instead, theentire cartridge unit is just pulled out and replaced as a unit with areplacement cartridge unit.

[0108] The structure, components and mode of operation of the first filmtransport station 27, the second film transport station 29, theinflation station 31, and the slitting station 35 are the same as thecorresponding mechanism, components and mode of operation describedabove with reference to the machine 11, and will not be reviewed in morespecific detail at this point.

[0109] The specific structure of the sealing station 33 of the machine101 is different from the machine 11 and will be described in moredetail below. However, the method of making seals across the inlet ports69 in the machine 101 is the same as the method of machine 11, as willbe understood from the description to follow.

[0110] One difference between the sealing station structure of themachine 11 and the sealing station structure of the machine 101 is inthe way that the heated sealing element and the sealing wheel are movedapart from one another during those times when the machine is stoppedbetween production runs of inflated pillows.

[0111] In the machine 11 (and as illustrated in FIG. 7) the heatedsealing element which is mounted on the end of the bar 81 is retractedaway from the sealing wheel 75. In the machine 11 the shaft 75 of theheated sealing wheel 75 is held in a fixed position with respect to theframe 13 in all modes of operation of the machine 11.

[0112] In the machine 101 the heated sealing element is held in a fixedposition with respect to the frame 13. The rotational shaft 77 of thesealing wheel 75 is mounted for rotation in a movable support bracket 75so that the sealing wheel 75 is movable toward and away from the heatedsealing element.

[0113] As best illustrated in FIG. 13, the support bracket 75 is mountedon a rod 82 of an actuator 84. The actuator 84 is mounted on a supportplate 86, and the support plate 86 is mounted on the main plate 13 ofthe machine 101.

[0114] The actuator 84 extends and retracts the rod 82 to move thesealing wheel 75 between the retracted position of the rod 82 shown inFIGS. 11 and 15 and the extended position shown in FIGS. 10 and 14.

[0115] In the retracted position illustrated in FIGS. 11 and 15 thesealing wheel 75 is positioned to let the film 19 remain out of contactwith the heated sealing element when the machine 101 is not operated ina production run.

[0116] In the extended position shown in FIGS. 10 and 14 the sealingwheel 75 is positioned to engage the film 19 and to press that film 19in sliding contact with the heated sealing element as the film 19 iscontinuously and uninterruptedly advanced through the machine during aproduction run of inflated pillows.

[0117] The force with which the film 19 is engaged in sliding contactwith the heated sealing element is determined by selecting the pressurelevel within the actuator 84.

[0118] As best illustrated in FIGS. 12, 10, and 14, the cartridge unit103 comprises a guide block 107 mounted in a fixed position on thesub-plate 105, two reels 109 and 111, each mounted for rotation on thesub-plate 105, and a guide post 113 mounted on the sub-plate 105.

[0119] The reels 109 and 111 are storage and take-up reels for a stripof covering fabric 72. The fabric 72 has a Teflon coating on the sideengaged in sliding contact with the film 19.

[0120] The strip of covering fabric 72 is trained around a guide post113 and into the guide slots 115 and 117 which are recessed within theouter and forward surfaces of the flanges 119 and 121 of the guide block107.

[0121] The way that the strip of covering fabric 72 is conveyed from thestorage roller 109, around the guide post 113, through the guide slot115, over the Nichrome wires 70, through the guide slot 117 and onto thereel 111 is best illustrated in FIGS. 10, 11, 14 and 15.

[0122] In a specific embodiment of the machine 101 the lower reel 111 isdriven, through reduction gearing, and by an electric motor (not shown),to pull the strip of covering fabric 72 across the Nichrome wires 70 ata relatively slow speed (a speed considerably slower than a speed atwhich the web of film 19 is transported through the machine 101 during aproduction run), but at a speed fast enough to insure that no part ofthe covering fabric 72 is ever in contact with the Nichrome wires 70long enough to permit any burn through of the fabric by the Nichromewires 70. The reel storage of the covering fabric 72 and the slowmovement of the fabric with respect to the Nichrome wires 70 duringoperation of the machine 101 thus insure that the area of the fabricengageable with the Nichrome wires is, in effect, renewed soon enough toprevent any burn through.

[0123] As best illustrated in FIGS. 12 and 15, the outer tips of theflanges 119 and 120 extend slightly beyond the outer surfaces of theNichrome wires 70. This insures that the covering fabric 72 is engagedwith the Nichrome wires 70 only when the sealing wheel 75 is moved tothe position shown in FIGS. 10 and 14 during a production run of themachine 101.

[0124] The strip of covering fabric 72 is held out of contact with theNichrome wires 70 when the machine 101 is not being operated in aproduction run of packaging.

[0125] While not illustrated in FIGS. 10-15, the Nichrome wires 70 areenergized by detachable leads 91 and 93 (as illustrated for the machine11 in FIGS. 9A-9G).

[0126] The sealing roller 75 of the machine 101 is laterally offsetoutwardly in the same way as the sealing roller 75 of the machine 11 soas to cause a bump in the film 19 at the sealing station 33. This helpsto create a dead zone adjacent the inlet port 69 to be sealed by causingthe web of film 19 to wrap around a part of the peripheral surface ofthe sealing roller 75 both in a circumferential direction and also in alateral direction (as described above with reference to the machine 11).

[0127] The machine 101 permits sealing the inlet port at a sealingstation by applying a heated sealing element directly to and in slidingcontact with the web of film and across the inlet port while the air inan inflated pillow is under pressure and as the web of film iscontinuously and uninterruptedly advanced through each of the firsttransport station, inflating station, sealing station, second transportstation and slitting station.

[0128] While we have illustrated and described the preferred embodimentsof our invention, it is to be understood that these are capable ofvariation and modification, and we therefore do not wish to be limitedto the precise details set forth, but desire to avail ourselves of suchchanges and alterations as fall within the purview of the followingclaims.

1. A machine for inflating and sealing pillow patterns in a web of filmwhile continuously and uninterruptedly advancing the web of film throughthe machine, said machine comprising, a first film transport station forgripping and advancing a web of film in the machine, said web of filmhaving uninflated pillow patterns and an uninflated inflation channelwhich are preformed in the web of film before the web of film is grippedat the first film transport station, said uninflated pillow patternscomprising multiple, spaced-apart, pillow patterns aligned along oneside of the inflation channel which extends longitudinally andcontinuously along the entire length of the web of film, each uninflatedpillow pattern having a narrow width inlet port extending generallytransversely to the longitudinally extending inflation channel andconnecting the uninflated pillow pattern to the uninflated inflationchannel so that when pressurized air is introduced into the inflationchannel the pressurized air can be transmitted through the inlet port toinflate the pillow pattern, an inflating station for inflating pillowsin the web of film, a sealing station for sealing inflated pillows bysealing the narrow width inlet port, a slitting station for slitting theinflation channel to permit removal of a strip of inflated, sealedpillows from the machine, and a second film transport station forgripping and advancing the web of film, said sealing station including asealing wheel and a heated sealing element biased toward engagement witha preselected force, and wherein a longitudinally extending portion ofthe web of film which contains the inlet ports is interposed between andpressed between the heated sealing element and the sealing wheel withone film surface engaged directly and in sliding contact with the heatedsealing element and the other film surface wrapped in rolling contactaround a part of the peripheral surface of the sealing roller as the webof film is continuously and uninterruptedly advanced through the sealingstation, and wherein the seal is formed complete and secure at the timethe web of film moves out of rolling contact with the sealing wheelwithout the need for additional pressing together of the web of filmafter the sealing station and without the need for additional cooling ofthe seal across the inlet port.
 2. The machine defined in claim 1wherein the web of film is gripped at the first film transport stationbetween a first pair of nip rollers and wherein the film is gripped atthe second film transport station between a second pair of nip rollersand wherein the sealing roller is positioned with respect to the firstand second pairs of nip rollers so as to cause the web of film to wraparound a part of the peripheral surface of the sealing roller both in acircumferential direction and also in a lateral direction to create adead zone in the area where the inlet port is being sealed.
 3. Themachine defined in claim 1 including adjustable means for adjusting theamount of said preselected force.
 4. The machine defined in claim 1wherein the sealing wheel is mounted for rotation at a fixed location inthe machine and the heated sealing element is movable toward and awayfrom the sealing wheel.
 5. The machine defined in claim 1 wherein theheated sealing element is mounted at a fixed location in the machine andthe sealing wheel is movable toward and away from the heated sealingelement.
 6. The machine defined in claim 2 wherein the axes of rotationof at least the second pair of nip rollers are canted at a slight anglewith respect to the axis of rotation of the sealing roller.
 7. Themachine defined in claim 2 wherein the second pair of nip rollers arerotated at a speed slightly faster than the speed of rotation of thefirst pair of nip rollers so as to maintain tension in the web of filmbetween the second and first pair of nip rollers.
 8. The machine definedin claim 1 wherein the heated sealing element has a longitudinaldimension, in the direction of movement of the web of film, which isabout the same as the width of the inlet port of a pillow pattern. 9.The machine defined in claim 1 wherein the inflating station includes aninflation tube which is inserted within the inflation channel of the webof film so that air under pressure can be introduced into the inflationchannel and wherein the inflation tube includes a generally ball-shapedoutlet end having a diameter which is substantially the same diameter asthe inside diameter of the inflation channel in the web of film andwherein the spherical shaped end of the inflation tube has an outercoating of Teflon for facilitating sliding movement of the inflationtube within the inflation channel of the web of film.
 10. The machinedefined in claim 1 wherein the heated sealing element comprises a fabriccovered Nichrome wire with a Teflon coating on the side of the fabricwhich is engaged in sliding contact with the web of film.
 11. Themachine defined in claim 1 wherein the sealing station includes aceramic part which mounts the Nichrome wire within the ceramic materialso that the ceramic part provides insulation against the spread of heatinto the mounting structure for the Nichrome wire.
 12. The machinedefined in claim 1 wherein the preformed pattern in the web of filmincludes a series of longitudinally spaced outlet ports on the side ofthe inflation channel opposite the side having the inlet ports formaintaining calibration of the pressure within the inflation channel andfor preventing excessive pressure buildup in the inflation channel andin the inflated pillows.
 13. The machine defined in claim 12 including asensor positioned to monitor flow of pressurized air out of the outletports and wherein the monitored flow can be used for counting the numberof inflated pillows produced in a production run and can be used alsofor maintaining accurate positioning of the web of film within themachine.
 14. The machine defined in claim 2 wherein the preformedpattern in the web of film includes a series of longitudinally spacedoutlet parts on the side of the inflation channel opposite the sidehaving the inlet ports and wherein the outlet ports provide an outletfor pressure in the inflation channel during the time when the filmadjacent the inlet port being sealed is being pulled closed in the deadzone of the film engaged with the periphery of the sealing wheel. 15.The machine defined in claim 5 including a cartridge unit which containsthe heated sealing element and which is constructed so as to be removedand replaced as a unit without the need to replace any individualcomponents of the cartridge unit, said cartridge unit comprising asub-frame, a guide block having an opening in one end for the heatedsealing element, at least one Nichrome wire mounted within the openingin the guide block, a storage reel and a take-up reel, a strip of fabricfor covering the Nichrome wire and wound on the storage reel and thetake-up reel, and a drive for rotating the take-up reel, said strip offabric having a Teflon coating on a side engageable in sliding contactwith a surface of the film at the sealing station and wherein the stripof fabric extends across said opening in the guide block so as to coverthe Nichrome wire when the sealing wheel is moved to a position in whichthe sealing wheel pushes the film against the fabric and the underlyingNichrome wire during continuous movement of the film through themachine.
 16. A machine for inflating and sealing pillow patterns in aweb of film while continuously and uninterruptedly advancing the web offilm through the machine, said machine comprising, a first filmtransport station for gripping and advancing a web of film in themachine, said web of film having uninflated pillow patterns and anuninflated inflation channel which are preformed in the web of filmbefore the web of film is gripped at the first film transport station,said uninflated pillow patterns comprising multiple, spaced-apart,pillow patterns aligned along one side of the inflation channel whichextends longitudinally and continuously along the entire length of theweb of film, each uninflated pillow pattern having a narrow width inletport extending generally transversely to the longitudinally extendinginflation channel and connecting the uninflated pillow pattern to theuninflated inflation channel so that when pressurized air is introducedinto the inflation channel the pressurized air can be transmittedthrough the inlet port to inflate the pillow pattern, an inflatingstation for inflating pillows in the web of film, a sealing station forsealing inflated pillows by sealing the narrow width inlet port, aslitting station for slitting the inflation channel to permit removal ofa strip of inflated, sealed pillows from the machine, and a second filmtransport station for gripping and advancing the web of film, saidsealing station including a sealing wheel and a heated sealing elementbiased toward engagement with a preselected force, the heated sealingelement being mounted at a fixed location in the machine and the sealingwheel being movable toward and away from the heated sealing element, andwherein a longitudinally extending portion of the web of film whichcontains the inlet ports is interposed between and pressed between theheated sealing element and the sealing wheel with one film surfaceengaged directly and in sliding contact with the heated sealing elementand the other film surface wrapped in rolling contact around a part ofthe peripheral surface of the sealing roller as the web of film iscontinuously and uninterruptedly advanced through the sealing station, acartridge unit which contains the heated sealing element and which isconstructed so as to be removed and replaced as a unit without the needto replace any individual components of the cartridge unit, saidcartridge unit comprising a sub-frame, a guide block having an openingin one end for the heated sealing element, at least one Nichrome wiremounted within the opening in the guide block, a storage reel and atake-up reel mounted for rotation on the sub-frame, a strip of fabricfor covering the Nichrome wire and wound on the storage reel and thetake-up reel, and a drive for rotating the take-up reel, said strip offabric having a Teflon coating on a side engageable in sliding contactwith a surface of the film at the sealing station, and wherein the stripof fabric extends across said opening in the guide block so as to coverthe Nichrome wire when the sealing wheel is moved to a position in whichthe sealing wheel pushes the film against the fabric and the underlyingNichrome wire during continuous movement of the film through themachine. and wherein the seal is formed complete and secure at the timethe web of film moves out of rolling contact with the sealing wheelwithout the need for additional pressing together of the web of filmafter the sealing station and without the need for additional cooling ofthe seal across the inlet port.
 17. A method of inflating and sealingpillow patterns in a web of film while continuously and uninterruptedlyadvancing the web of film through a machine, said method comprising,gripping a web of film at a first film transport station to draw a webof film from a store, said web of film having an uninflated pillowpattern and an uninflated inflation channel which are preformed in theweb of film before the web of film is gripped at the first filmtransport station, said uninflated pillow patterns comprising multiple,spaced-apart, pillow patterns aligned along one side of the inflationchannel which extends longitudinally and continuously along the entirelength of the web of film, each uninflated pillow pattern having anarrow width inlet port extending generally transversely to thelongitudinally extending inflation channel and connecting the uninflatedpillow pattern to the uninflated inflation channel so that whenpressurized air is introduced into the inflation channel the pressurizedair can be transmitted through the inlet port to inflate the pillowpattern, introducing pressurized air into the inflation channel in theweb of film at an inflating station and inflating at least one of pillowpatterns prior to the time the web of film is transported through asealing station, gripping the web of film at a second film transportstation to continuously advance the web of film from the first transportstation to and through the sealing station and then to and through thesecond film transport station, maintaining pressure in the inflatedpillow pattern during the time that the web of film is being transportedthrough the sealing station, sealing the inlet port at the sealingstation by applying a heated sealing element directly to and in slidingcontact with the web of film and across the inlet port while the air inthe inflated pillow is under pressure and as the web of film iscontinuously advanced through the sealing station, said sealing stationincluding a sealing roller disposed opposite the heated sealing element,said sealing roller having part of its periphery engaged in rollingcontact with the film at the sealing station on the side of the filmopposite that engaged in sliding contact with the heated sealingelement, positioning the sealing roller to create a dead zone in thearea of the film engaged in rolling contact with the periphery of thesealing roller, and forming the seal complete and secure by the time theweb of film moves out of contact with the sealing wheel without the needfor additional pressing together of the film after the sealing stationand without the need for additional cooling of the seal across thesealed inlet port.
 18. The method defined in claim 17 wherein thepre-formed pattern in the web of film includes a series oflongitudinally spaced outlet ports on the side of the inflation channelopposite the side having the inlet ports and wherein the outlet portsprovide an outlet for pressure in the inflation channel during the timewhen the film adjacent the inlet port is being pulled closed in the deadzone of the film engaged with the periphery of the sealing wheel. 19.The method defined in claim 17 wherein the pattern on the web of filmincludes longitudinally spaced outlet ports connected to the side of theinflation channel opposite the side of the inflation channel having theinlet ports and wherein the outlet ports maintain calibration of thepressure within the inflation channel and prevent excessive pressurebuildup in the inflation channel and in the inflated pillows.
 20. Themethod defined in claim 19 including sensing the flow of pressurized airout of the outlet ports and monitoring the flow to count the number ofpillows inflated in a production run of the film through the machine.21. A web of film formed with a pattern of pillows to be inflated andsealed and then used in packaging, said web of film and patterncomprising, two sheets of plastic film overlaid one on the other to forma web of film, said web of film being sealed together in a pattern, saidpattern comprising, an inflation channel which extends longitudinallyand continuously along the entire length of the web of film, multiple,spaced-apart, pillow patterns aligned along one side of the inflationchannel, each pillow pattern having a narrow width inlet port extendinggenerally transversely to the longitudinally extending inflation channeland connecting the pillow pattern to the inflation channel so that whenpressurized air is introduced into the inflation channel, thepressurized air can be transmitted through the inlet port to inflate thepillow pattern, a plurality of longitudinally spaced-apart outlet portson the side of the inflation channel opposite the side having the inletports, and wherein the outlet ports are constructed to permit exhaustingthe overflow of pressure in the inflation channel while the pillowpatterns are being inflated and being sealed under pressure.